球化退火和高温回火形成的组织有何区别

球化的过程中会加入一些孕育剂和球化剂等 碳自然会降低 一吨炉的话大约降0.2左右

In this research GCr15 of the grains will be refined ball annealing and process.
GCr15 steel,prepare for heat treatment using spheroidizing annealing,is to make the steel spheroidization,improve carbide steel processing performance,and for the quenching organize well prepared.Finally,by grain refinement process heat to improve the performance of GCr15 steel,especially the fatigue life of improved,there are evident effects.
This topic with resistance furnace,microscope,hardness tester etc equipment,through general spheroidizing annealing,isothermal spheroidizing annealing,rapid spheroidizing annealing (namely piece.modified) prepare comparative experiments,discussion of the spheroidizing treatment heat best effect.In the final heat treatment,through conventional quenching + cryogenic tempering and circulation quenching process is compared,and get the best fine grains process.
Experiments show that the rapid prepare heat treatment spheroidization annealing (conditioning) get good results of spheroidal graphite.In the final heat treatment using circular quenching grain refinement effect is good,three times quenching refinement of grain can achieve 10 levels.
Keywords:GCr15 steel spheroidizing annealing grain refinement heat treatment

铁水氧化在球化处理时会大量消耗球化剂中的镁和稀土等球化元素,造成石墨核心减少,石墨颗粒增大,当残镁低于0.025%时则会出现球化衰退.解决的办法有：可添加脱氧剂进行脱氧除气；低温保温,表面覆盖保温剂；增加球化剂的加入量,强化孕育等.

730-750保温4小时,随炉冷至650-670保温2小时,炉冷至常温

铸铁在结晶过程中,碳以石墨形态 析出的现象称为石墨化
答案A

球化处理就是让铸铁中的碳的存在形式为球状；
孕育处理：1、可以作为石墨球的核心；
2、能减少反球化剂元素加入所引起的白口倾向,阻碍碳化物的形成,促进碳成长为球状；
3、孕育剂的加入能创造较多的石墨结晶核心,使共晶团数目增多,细小并均匀分布,从而提高机械性能；
4、此外,孕育处理对球化有保护作用,可以延缓球化衰退.

Ferrous materials heat treatment includes several important operation,often be crowned as follows these descriptions,such as normalizing,nodularity,stress elimination,annealing,quenching and tempering and atherosclerosis

GCr15球化退火最适宜的加热温度为780-800℃,若低于下限温度,加热温度过低时,原始片状珠光体还没有完全溶解或团聚,冷却时除有球状珠光体外,还会有部分细片状珠光体,这是加热不足的组织,其硬度也会偏高.

硬度偏低是多少?这种钢正火硬度在HB220左右. 查看原帖>>
求采纳

铸造中的孕育和球化处理一般是针对球铁而言的,球铁是用灰铁成分的铁液经球化处理和孕育处理得到的.将球化剂加入铁水的操作过程叫球化处理.我国常用的球化剂有镁、稀土或稀土硅镁合金.纯镁的球化作用很强,球化率高,容易获得完整的石墨.但是纯镁又是很强的阻碍石墨化的元素,有增大铸铁白口化的倾向.由于纯镁的沸点远低于铁水温度,因此纯镁加入铁水中沸腾飞溅、烧损严重,需要采用压力加镁办法,处理工艺和设备较为复杂.而且铸件的收缩、疏松夹渣、皮下气泡等缺陷较为严重.
因此镁及稀土元素都强烈组织石墨化,铁水经球化处理后容易出现白口,难以产生石墨核心.因此,球化处理的同时,必须进行孕育处理.孕育剂必须含有强烈促进石墨化的元素,通常采用含硅量是75%的硅铁和硅钙合金.经孕育处理后的球铁,石墨球铁量增加,球径减小,形状圆整,分布均匀,从而显著改善了球铁的机械性能.